Algodoo

Well, I will be honest. The mechanics are indeed simple. However, if you look at a true pump-action shotgun or rifle, the fore-grip does not actually push the shells or rounds back. A spring in the tube magazine does that, with the action disabling a catch that holds the shells in the magazine. Using cams and some other mechanisms, as well as timing, the rearmost shell will be released, but the one in front of it will not. The mechanisms to actually feed the shell or casing into the chamber only activate when the fore-grip is pushed forward (using a dog that pivots back and forth, but applies leverage to the carrier (the bar that tilts up towards the chamber) with forward motion. Take a look at my NG-SG-1. It's mechanics are far from perfect, but the skin can be moved back so you can reveal the mechanisms and study them. I give your scene 8/10 for a great effort , but under-developed mechanisms are what kept it from being one or two points higher.

its true ngphil
D